A method of forming an imaging fibre apparatus comprises arranging rods to form a plurality of stacks each comprising a respective plurality of rods, wherein: for each stack, the respective plurality of rods comprises rods having different core sizes, the rods of different core sizes being arranged in a selected arrangement, and the rods of different core sizes being arranged such that each stack has a respective selected shape; wherein the selected shape or shapes are such that the stacks stack together in a desired arrangement; the method further comprising: drawing each of the plurality of stacks; stacking together the plurality of drawn stacks together in the desired arrangement to form a further stack; drawing the further stack; and using the drawn further stack to form an imaging fibre apparatus, wherein the selected arrangement of the rods in each stack and the selected shape or shapes of the stacks are such that the further stack comprises a repeating pattern of rods of different core sizes.

A method of forming an imaging fibre apparatus comprises arranging rods to form a plurality of stacks each comprising a respective plurality of rods, wherein: for each stack, the respective plurality of rods comprises rods having different core sizes, the rods of different core sizes being arranged in a selected arrangement, and the rods of different core sizes being arranged such that each stack has a respective selected shape; wherein the selected shape or shapes are such that the stacks stack together in a desired arrangement; the method further comprising: drawing each of the plurality of stacks; stacking together the plurality of drawn stacks together in the desired arrangement to form a further stack; drawing the further stack; and using the drawn further stack to form an imaging fibre apparatus, wherein the selected arrangement of the rods in each stack and the selected shape or shapes of the stacks are such that the further stack comprises a repeating pattern of rods of different core sizes.

There is provided a method for making an optical element having a textured surface. The method comprises the steps of: a) providing a plurality of primary optical fiber segments, each primary fiber segment comprising one or more cores; b) bundling the primary fiber segments into an assembly with the cores of said primary fiber segments extending parallely; c) transforming the assembly into a secondary structure comprising the parallely extending cores; and d) etching a surface of the secondary structure according to an etch profile of said secondary structure, the etch profile being defined by the parallely extending cores, thereby forming the textured surface of the optical element. An optical element having a textured surface is also provided.

There is provided a method for making an optical element having a textured surface. The method comprises the steps of: a) providing a plurality of primary optical fiber segments, each primary fiber segment comprising one or more cores; b) bundling the primary fiber segments into an assembly with the cores of said primary fiber segments extending parallely; c) transforming the assembly into a secondary structure comprising the parallely extending cores; and d) etching a surface of the secondary structure according to an etch profile of said secondary structure, the etch profile being defined by the parallely extending cores, thereby forming the textured surface of the optical element. An optical element having a textured surface is also provided.

Optical waveguide cores having refractive index profiles that vary angularly about a propagation axis of the core can provide single-mode operation with larger core diameters than conventional waveguides. In one representative embodiment, an optical waveguide comprises a core that extends along a propagation axis and has a refractive index profile that varies angularly about the propagation axis. The optical waveguide can also comprise a cladding disposed about the core and extending along the propagation axis. The refractive index profile of the core can vary angularly along a length of the propagation axis.

Optical waveguide cores having refractive index profiles that vary angularly about a propagation axis of the core can provide single-mode operation with larger core diameters than conventional waveguides. In one representative embodiment, an optical waveguide comprises a core that extends along a propagation axis and has a refractive index profile that varies angularly about the propagation axis. The optical waveguide can also comprise a cladding disposed about the core and extending along the propagation axis. The refractive index profile of the core can vary angularly along a length of the propagation axis.

A method for manufacturing a fan-in-fan-out device which does not require processing of a small-diameter hole and improves work efficiency of installation of an optical fiber, includes: arranging a first holding member in a hole of a second holding member, the hole being larger than an outer diameter of the first holding member, and holding a plurality of optical fibers between the first holding member and the second holding member respectively along a plurality of grooves formed on an outer periphery of the first holding member or an inner periphery of the hole of the second holding member; heating and integrally melting the arranged first holding member, the plurality of held optical fibers, and the second holding member in a portion including an axial end portion of the second holding member; and drawing the melted portion.

A method for manufacturing a fan-in-fan-out device which does not require processing of a small-diameter hole and improves work efficiency of installation of an optical fiber, includes: arranging a first holding member in a hole of a second holding member, the hole being larger than an outer diameter of the first holding member, and holding a plurality of optical fibers between the first holding member and the second holding member respectively along a plurality of grooves formed on an outer periphery of the first holding member or an inner periphery of the hole of the second holding member; heating and integrally melting the arranged first holding member, the plurality of held optical fibers, and the second holding member in a portion including an axial end portion of the second holding member; and drawing the melted portion.

A fiber optic imaging element includes medium-expansion and a fabrication method including: (1) matching a core glass rod with a cladding glass tube to perform mono fiber drawing; (2) arranging the mono fibers into a mono fiber bundle rod, and then drawing the mono fiber bundle rod into a multi fiber; (3) arranging the multi fiber into a multi fiber bundle rod, and then drawing the multi fiber bundle rod into a multi-multi fiber; (4) cutting the multi-multi fiber, and then arranging the multi-multi fiber into a fiber assembly buddle, then putting the fiber assembly buddle into a mold of heat press fusion process, and performing the heat press fusion process to prepare a block of the fiber optic imaging element with medium-expansion; and (5) edged rounding, cutting and slicing,

A fiber optic imaging element includes medium-expansion and a fabrication method including: (1) matching a core glass rod with a cladding glass tube to perform mono fiber drawing; (2) arranging the mono fibers into a mono fiber bundle rod, and then drawing the mono fiber bundle rod into a multi fiber; (3) arranging the multi fiber into a multi fiber bundle rod, and then drawing the multi fiber bundle rod into a multi-multi fiber; (4) cutting the multi-multi fiber, and then arranging the multi-multi fiber into a fiber assembly buddle, then putting the fiber assembly buddle into a mold of heat press fusion process, and performing the heat press fusion process to prepare a block of the fiber optic imaging element with medium-expansion; and (5) edged rounding, cutting and slicing,